Switching Element Diagnostics Using Pseudo Fault Signals

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing failure detection devices for switching elements do not perform failure diagnosis on abnormality detection circuits such as overvoltage and overcurrent detection circuits while ensuring a conduction state.

Innovation Solution

A diagnostic device that includes a first signal output unit to simulate an abnormal state, a detection unit to detect the ON state of a switching element, a determination unit to determine failures, and current cut switches to manage power flow, allowing failure diagnosis on switching elements and abnormality detection circuits in a redundant system with redundant storage batteries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If failure diagnosis is executed on switching elements while ensuring conduction state, then reliability of switching element detection is improved, but abnormality detection circuits cannot be diagnosed

Engineering Contradiction:

Improveswitching element failure detectionVSAvoidabnormality detection circuit diagnosis capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system performs preliminary actions by outputting a pseudo signal to simulate an abnormal state before actual failure occurs. This allows the abnormality detection circuit to be tested in advance under controlled conditions, enabling diagnosis of both the detection circuit and switching element without waiting for actual failures.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A pseudo signal is introduced as an intermediary to simulate abnormal states. This intermediary signal allows the system to test the abnormality detection circuit's response without requiring actual abnormal conditions, enabling safe and controlled diagnosis of both the detection circuit and switching elements.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If redundant storage battery supplies power to backup load, then system reliability is improved, but power consumption increases

Engineering Contradiction:

Improveredundant system availabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The current cut switch periodically disconnects the backup load from the redundant storage battery when the main storage battery is normal. This periodic action reduces unnecessary power consumption while maintaining the backup capability when needed, balancing energy efficiency with system reliability.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system discards the backup power connection when the main power source is functioning normally, and recovers it when needed. The current cut switch manages this by disconnecting the backup load during normal operation and reconnecting it when the main storage battery exhibits abnormalities, optimizing power usage while maintaining redundancy.

Inventive Principle:

Principle #34Discarding and recovering

Data Source

PatentUS20250321274A1Diagnostic device for switching element and abnormality detection circuit

Publication Date: 2025.10.16 YAZAKI CORP

AI summary

A diagnostic device includes a microcomputer that outputs a pseudo signal for simulating an abnormal state to an overvoltage detection circuit and a low voltage detection circuit, and a detection circuit that detects ON of a switching element after the pseudo signal is output by the microcomputer. The microcomputer determines a failure of the switching element or failures of the overvoltage detection circuit and the low voltage detection circuit when ON of the switching element is detected by the detection circuit.